The polymyxins belong to cyclic polypeptide antibiotics. The first notes about polymyxin as antibiotics comes from a period of fifty years from the last century. We divided polymyxins to A, B, C, D, E, F, M, S and T.
Polymyxin B represents a mixture of polymyxins B1, B2, B3 and B11. The composition of polymyxins listed above and representation of amino acid units and fatty acids are as follows:
L-L-D-L-AntibioticThreonineLeucineFenylalanineDBAFatty acidPolymyxine B12116MOAPolymyxine B22116MHAPolymyxine B32116OctanoylDBA—2,4 diaminobutyrateMOA—6-methyloktanoylMHA—6-methylheptanoyl
Polymyxin B is an antibiotic for human purposes, effective for Gram-negative rods, especially for Shigela, Salmonela, Escherichia and Klebsiela. It is not effective for Proteus, Providentia, Bactericides and Serratia and generally for fungi and Gram-positive bacteria. It is not absorbed by digestion, very weakly is absorbed to tissues, does not penetrate to the cells and it is secreted by the kidney.
The production microorganism: Bacillus polymyxa 
Published patents relating to polymyxin B fermentation field by using strain Bacillus polymyxa are as follows:
1. U.S. Pat. No. 2,595,605
In the patent is described the composition of fermentation media. The addition of corn flour increased production of antibiotics from 1200 IU/ml to 1800-2000 IU/ml for 88 hours of cultivation, what is equal to a concentration of polymyxine 0.251 g/l, measured by HPLC. It is not mentioned which type of polymyxin it was.
2. U.S. Pat. No. 2,571,104
In the patent is described the influence of mutagenesis by UV light to cells of a production strain, whereby an isolate with 5-times higher production of polymyxin in comparison with parental strains is obtained. This isolate has name Bacillus polymyxa NRRL B-719, it is stable, its production characteristic is kept till the 40th generation, utilized the following carbon sources: glucose, xylose, starch, and as a suitable source of amino acids are corn-steep, peanut flour, soya flour, yeast extract, ground corn. In the patent is described the way of one batch feed of fermentation media at 72 hour of cultivation. Production yield of polymyxin is 1000 IU/ml after 116 hours of cultivation, which is equal to a concentration of 0.125 g/l.
3. U.S. Pat. No. 2,602,041
The patent described improved isolation process and killing cells of production strain by using 0.4% solution of chloroform.
According the patent search was find patent of Russia, related to process of polymyxine fermentation M and Japanese patents, related to polymyxine fermentations F, T1, S1.